1. Field of the Invention
The invention relates to apparatus for the application of film to an air-permeable substrate and more particularly to an apparatus and continuous method for vacuum lamination of film onto a wood composite substrate.
2. Description of Related Technology
The application of a thin decorative and/or protective plastic film to a surface of a substrate that is substantially planar, but includes a textured or sculptured surface has been conventionally performed by utilizing roll laminators to press the film against the substrate. If the substrate is porous, the fidelity (i.e. conformity of the film to the surface of the substrate) of the laminate may be improved by pulling a vacuum at the side of the substrate opposite the film-covered surface in order to draw the film toward the substrate. Vacuum lamination apparatus which have been utilized in a batch or cyclic lamination processes typically include a perforated plate connected to a vacuum source. The substrate is placed on the plate with the side of the substrate opposite the film-covered surface in contact with the perforated plate. A vacuum is pulled through the perforated plate, thereby drawing the plastic film toward the substrate.
The desirability of laminating film to an air-permeable substrate in a continuous process has lead to experimentation with perforated conveyor belt systems moving across stationary vacuum chambers. However, such systems have failed to provide a reliable seal between the substrate and the vacuum source, particularly if film is being laminated to a textured and/or machined surface of the substrate.